Photocopiers use a variety of replaceable toner cartridges to provide toner to image forming mechanisms. In some examples, toner cartridges include feeding members, such as augers, sweeping blades and the like that rotate to move toner within the toner cartridge toward a discharge opening and from there into the image forming apparatus. In other examples, the toner cartridge is rotated and includes features therein that move the toner toward the toner discharge opening. Many rotatable toner cartridges include drive transmission features that communicate rotational motion from a driving mechanism in the photocopier to the toner cartridge, and thereby rotate the cartridge. These drive transmission features, in yet other examples, transmit rotational force directly to the toner cartridge filled with toner. The inertia of the filled cartridge is considerable and in some cases the drive transmission features fail because of corresponding rotational stresses, substantially preventing rotation of the cartridge and dispensing of toner. Additionally, a failed drive transmission feature may be difficult to remove from the photocopier and require considerable maintenance before another toner cartridge may be used.
In still other examples, rotatable toner cartridges include drive coupling members with the drive transmission features, and the drive coupling members are at least partially disengageable from the cartridges while the cartridges are in use. In one example, the drive coupling member is pulled away from the toner cartridge to form a toner discharge opening between the drive coupling member and the toner cartridge. The drive coupling member is moveably coupled with the toner cartridge by supports that extend therebetween and allow for discharge of toner. Similarly to the drive transmission feature, described above, the supports experience significant rotational stress because of the inertia of the filled toner cartridge and may experience failure. Moreover, the drive coupling member and supports must be carefully designed and manufactured to properly engage with the toner cartridge and the driving mechanism of the image forming apparatus to provide the desired size for the discharge opening and correctly position the toner cartridge in the image forming apparatus for rotation. Manufacturing of a toner cartridge with moveable parts that require careful dimensioning, as described above, is expensive and time consuming. Additionally, the disengaged drive coupling member can misalign with the toner cartridge when the image forming apparatus attempts to close the cartridge. The misalignment causes spilling of toner from the cartridge as it is removed from the image forming apparatus.
In yet other examples, toner cartridges include feeding members that are immobile with respect to the cartridge and move toner through the toner cartridge as the cartridge is rotated. For example, at least some toner cartridges include a lattice work feeding member that extends across a diameter of the cartridge. The feeding member includes a complicated arrangement of ramps, projections and through holes that transport toner toward the discharge opening of the cartridge. Toner is scooped by the ramp and projection and slides down the ramp and projection toward the discharge opening. At least some of the scooped toner falls through the through hole to fluidize the toner within the cartridge and prevent toner clumping. The lattice work feeding member requires complicated molding and/or machining and must be coupled within the interior of the toner cartridge. Forming the lattice work feeding member is therefore expensive and requires additional labor to install within the cartridge.
The present inventors have recognized that what is needed are toner cartridges and methods for making the same that address the above issues. The present inventors have further recognized that what is needed is a toner cartridge that maintains a minimum of easily manufactured parts and a minimum number of drive transmitting parts that are moveable with respect to the cartridge.